单项选择题
For a frequency distribution, the class midpoint is:
单项选择题 收银六步骤的排序是正确的①欢迎顾客②确认点餐内容③点餐④收银找零⑤建议性销售⑥呈递收银条指引顾客()
未知题型 Please convert active voice into passive voice in the following sentence. We should attach importance to environmental protection.
单项选择题 It is one of the most ___________works of imagination in the language.